Differential pressure measuring arrangements with differential pressure lines serve especially for flow measurement or filter monitoring, wherein differential pressure lines are connected in the flow direction above and below means causing a differential pressure, for example, a diaphragm or a Venturi nozzle, or a filter, to media containing lines, in order to transfer the differential pressure by means of the medium to a differential pressure measuring transducer of the differential pressure measuring arrangement. During operation of such measuring arrangements, the differential pressure lines can become plugged, whereby reliable measuring is degraded. There are, consequently, efforts known, which are directed at early detection of plugging of differential pressure lines.
German patent application DE 10 2013 110 059 A1 describes a differential pressure measuring arrangement, which detects plugged differential pressure lines based on a correlation of a differential pressure measurement signal, which shows a pressure difference between a first media pressure and a second media pressure, and a temperature signal, which correlates with a temperature of a differential pressure line.
DE 10 2013 110 059 A1, in such case, detects plugged differential pressure lines using only measured values (differential pressure and temperature), which were registered by the differential pressure measuring arrangement itself. This can lead to false alarms, i.e. claims of plugging, when the differential pressure lines really are not plugged. For example, the temperature of the differential pressure line registered by a temperature sensor of the differential pressure measuring arrangement slightly rises and simultaneously the flow in the process is slowly increased, for example, by increasing the RPM of a pump. In such case, a processing unit of the differential pressure measuring arrangement would detect a correlation between the temperature rise and the differential pressure and likewise diagnose an elevated signal noise, based on which a plugged differential pressure line would be determined and, in given cases, a false alarm output, even though plugging would not actually be present.